• 2019 Update 7
  • 03/31/2020
Contents

Multiple Endpoints Support

Intel® MPI Library Developer Guide for Linux* OS
The traditional MPI/OpenMP* threading model has certain performance issues. Thread safe access to some MPI objects, such as requests or communicators, requires an internal synchronization between threads; the performance of the typical hybrid application, which uses MPI calls from several threads per rank, is often lower than expected.
The PSM2 Multiple Endpoints (Multi-EP) support in the Intel® MPI Library makes it possible to eliminate most of the cross-thread synchronization points in the MPI workflow, at the cost of some limitations on what is allowed by the standard
MPI_THREAD_MULTIPLE
thread support level. The Multi-EP support, implemented with
MPI_THREAD_SPLIT
(thread-split) programming model, implies several requirements to the application program code to meet, and introduces a few runtime switches. These requirements, limitations, and usage rules are discussed in the sections below.

Product and Performance Information

1

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804